Also, if you want to be in on the playtest, they've said how you can jump in.
From the announcement:
Paizo, Inc., leading publisher of tabletop roleplaying and adventure card games, announces today a special Halloween-spirited preview of next summer’s major hardcover release, Pathfinder Roleplaying Game: Occult Adventures. A huge playtest preview of the book’s six new classes is now live on paizo.com to kick off a month-long open playtest process that allows Pathfinder RPG players to share their experiences with the Paizo staff. Playtester feedback will be incorporated into the final book, which is slated for release in July, 2015.
Occult Adventures will feature six new classes for the Pathfinder Roleplaying Game, and an entirely new system for psychic magic. The 256-page hardcover book will have details on occult concepts, such as séances, aura-reading, and occult rituals, as well as tons of new spells, magic items drawn from occult legends, and ways to add psychic and occult elements to existing Pathfinder classes. The new 20-level base classes included in Occult Adventures are the reality-warping kineticist, the spirit-infused medium, the manipulative mesmerist, the relic-wielding occultist, the mind-master psychic, and the phantom-bonded spiritualist.
Participants in the playtest can download and review the six new classes, use them in their games, or otherwise test the power, balance, and overall clarity of the new classes. Via the paizo.com mesageboards, playtesters will directly communicate with the Pathfinder RPG design team and other players, helping to polish and refine the classes, while also taking part in surveys and brainstorms to help make Occult Adventures a fantastic new part of the Pathfinder RPG.